Collapsible framework, such as a display stand, and an articulation joint for such framework

ABSTRACT

A collapsible three dimensional framework includes a plurality of tubular rods ( 10 ) connected to each other by means of articulation joints. Each of the joints consists of a block divided into two matching pieces ( 28, 30 ). The block has a plurality of cavities ( 18   a   , 18   b ) each of which is open on a respective side face and on a back face of the block. The ends of respective rods ( 10 ) are inserted in the cavities ( 18   a   , 18   b ) and are connected to the block by transverse pivot pins ( 24 ). Each of the cavities has articulation seats ( 32 ) which received the pivot pins ( 24 ) When the two pieces ( 28, 30 ) of the block are secured to each other, the pivot pins ( 24 ) are entrapped in respective seats ( 32 ). The two pieces ( 28, 30 ) of the block are clamped together by releasable fastening means such as a screw ( 40 ) and a nut ( 42 ).

This is a National stage entry under 35 U.S.C. §371 of PCT ApplicationNo. PCT/EP01/07044 filed Jun. 21, 2001; the disclosure of which isincorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to a collapsible framework, such as adisplay stand, according to the preamble of claim 1.

Collapsible frameworks according to the preamble of claim 1 are knownfrom documents EP-A-0 219 201, DE-U-87 04 312 and WO 89/09006.

In these known frameworks the blocks constituting the joints are in asingle piece, the opposite sidewalls of their cavities which receive theends of the rods have holes and the ends of the rods have holes as well.The rods are articulated to the blocks by pivot pins inserted in theholes.

One of the advantages of the frameworks of this kind, in addition tobeing collapsible, is that they allow to assemble frameworks ofdifferent shapes and dimensions from tubular rods of the same type andthe same length and to connect these rods by means of joints of the sametype.

The connection of the rods to the joints by means of pivot pins which,according to the known prior art, are inserted in the blocks and,transversally, in the ends of the rods, may be a relatively long and:difficult task because of which the time required to assemble aframework can turn out to be rather long.

SUMMARY OF THE INVENTION

The object of the invention is to provide a collapsible framework of thetype set forth which can be assembled in times shorter than thoserequired by the known frameworks, thanks to the fact that thearticulated connections of the rods to the joints can be performed moreeasily.

According to the invention, this object is attained by means of acollapsible framework according to the characterizing portion of claim1.

The assembly of a framework according to the invention is simpler andquicker than that of the known frameworks, because the operation bywhich each of the rods is pivotally coupled to a joint or block iseasier.

In order to carry out this connection, while the two pieces of the blockare taken apart, the ends of the rods are inserted into thecorresponding cavities, whereupon the pivot pins which are fastened tothe rods become engaged in the articulation seats. Once this engagementhas been performed, it suffices to complete the block by securing itstwo pieces to each other, whereupon the pivot pins remain entrapped inthe seats within the block.

The invention also relates to an articulation joint as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will become more clear from the reading of the detaileddescription which follows, reference being made to the appendeddrawings, given by way of non-limiting example, and in which:

FIG. 1 is a perspective view of a portion of a collapsible frameworkaccording to the invention,

FIG. 2 is a partially exploded, perspective view on a larger scale of ajoint of the framework of FIG. 1,

FIG. 3 is a perspective view on a larger scale of the region of a jointindicated III in FIG. 1,

FIG. 4 is an exploded perspective view which shows the joint with itstwo pieces taken apart from each other, as well as an end of a rod;

FIG. 5 is a perspective view on a larger scale of the region indicated Vin FIG. 1,

FIG. 6 is a partial cross-section taken in the plane indicated VI—VI inFIG. 2,

FIG. 7 is a perspective view of a profiled peg or button which may beused instead of the profiled pegs or buttons of FIG. 2, and

FIG. 8 is a perspective view on a larger scale of the region indicatedVIII in FIG. 1.

Referring to FIG. 1, a three-dimensional collapsible framework has aplurality of tubular rods 10 which are connected with each other bymeans of articulation joints 12.

The framework further includes tubular spacer rods 14, associated withopposite joints 12.

In FIG. 1 removable slats 16 are shown which are coupled tocorresponding joints 12 in a manner which will be explained below.

The slats 16 constitute a frame for supporting a panel or the like andcan contain a core of ferrous material so that a panel or the like canbe affixed to the slats by means of magnets.

Referring to FIGS. 2 to 4, each of the joints 12 consists of a blockhaving a substantially parallelepipedal shape.

The block 12 has a plurality of cavities 18, four in number in theembodiment shown.

Each of the cavities 18 is open on a respective lateral face 20 and on aback face 22 of the block 12.

The ends of respective rods 10 are inserted in the cavities 18 (FIG. 3),and such ends are connected to the block 12 by transverse pivot pins oneof which, indicated 24, is shown in FIG. 4.

The transverse pivot pins 24 are fastened to respective rods 10 andproject from the rods in opposite positions.

Preferably, as shown, each transverse pivot pin 24 is constituted by aresilient tubular split dowel which is driven into diametricallyopposite holes 26 of the respective rod 10.

The block 12 is divided into two pieces 28, 30 which match to each otheraccording to a separation plane.

In a direction perpendicular to this separation plane the piece 28 has arelatively great thickness, while the other piece 30 has a relativelysmall thickness.

The cavities 18 are provided for the major part, as indicated at 18 a inFIG. 4, in the piece 28 of greater thickness of the block 12 and arecompleted by portions of cavity (indicated 18 b in FIG. 4) which areprovided in the piece 30 of smaller thickness of the block 12.

Still referring to FIG. 4, articulation seats 32 for the pivot pins 24of the rods 10 are formed in the piece 28 of the block 12.

The seats 32 are open to the corresponding cavities 18, or better to sayto the cavity portions 18 a, in laterally opposite positions.

As can be seen in FIG. 4, the articulation seats 32 are in the form ofrecesses which are open both to the corresponding cavity portions 18 aand on a face of the block piece 28 which coincides with the separationplane between the two pieces 28, 30.

The other piece 30 of the block 12 has, in the matching plane with thepiece 28, flat surfaces 36 which, when the two pieces 28, 30 are joined,close the openings of the recesses 32.

In order to pivotally connect a rod 10 to a block 12, while the twopieces 28, 30 are taken apart as in FIG. 4, it suffices to introduce theend of the rod 10 into the corresponding cavity portion 18 a until theprojecting ends of the pivot pin 24 are engaged in the recesses 32,after which the two pieces 26, 30 of the block 12 are joined to eachother and the pivot pin 24 remains entrapped.

The two pieces 28, 30 of the block are then secured together byreleasable fastening means. Preferably, as shown in FIGS. 2 and 4, thesesecuring means are constituted by a tightening screw 40 which centrallyextends in the two pieces 28, 30 of the block 12, perpendicularly to itsseparation plane.

A tightening nut 40 is associated with the screw 40.

Reference will now be made to FIG. 5 to describe one of the spacertubular rods 14.

The function of the spacer rods 14 is to ensure that thethree-dimensional framework remains in a stable configuration in theunfolded condition shown in FIG. 1.

Each of the spacer rods 14 is preferably in two sections 44, 46, each ofwhich is fixed to a respective joint or block 12 in a manner which willbe described below.

The two sections 44, 46 are provided with mutual coupling means.Preferably, the section 44 has, at the end thereof which is remote fromthe corresponding block 12, a mushroom-shaped appendage 48 of plasticsmaterial which fits into a tulip-shaped resilient clamp which is locatedat the end remote from the corresponding block 12.

The section 44 has a sleeve which is adapted to slide thereon and which,when the mushroom-shaped appendage has been fitted into the clamp 50, isbrought by sliding to a position in which it surrounds the clamp both toprevent the clamp from expanding, and to impart an aesthetic aspect tothe spacer rod 14.

Each of the sections 44, 46 is secured to the respective block 12 by thesame central screws which keep the two pieces 28, 30 of the blocks 12together.

These screws, indicated 40 a, have a length which is larger than that ofthe screws 40 which keep the two pieces 28, 30 together when no spacerrod 14 is associated with the corresponding block 12.

An internally threaded bushing 54 is driven into the end of each of thesections 44, 46 which faces the corresponding block 12, the shank of thecorresponding screw 40 a being screwed within said bushing.

The bushing 54 can replace the nut 42 shown in FIG. 4, or be provided inaddition to the nut 42.

Returning to FIG. 2, a front face 56 of the block 12, opposite to itsback face 22, has pegs 58 which are substantially diabolo-shaped andconstitute buttons to which accessories can be fixed. Preferably, asshown, the pegs 58 are constituted by pieces of plastics material whichare distinct from the corresponding piece 28 of the block 12.

Each peg 58 has a foot portion 60 which is fitted into a correspondingseat 62 provided in the front face 56.

Preferably, as shown in FIGS. 2 and 6, each foot portion 60 includes afirst cylindrical section 64 of larger diameter, from which thereextends a second resilient tubular cylindrical section 66 of smallerdiameter, which ends with an outer annular rim 68.

The corresponding seats 62 have in their turn a first cylindricalsection 70 of larger diameter, to receive the said first section 64, anda second cylindrical section 72 of smaller diameter, to receive the saidsecond section 66.

The second section 66 of the foot portion 60 extends through a wall 74of the block piece 28. The arrangement is such that the rim 68, when thefoot portion 60 is being pushed home, engages with a snap fit around theinner mouth of the second section 72 of the seat 62.

FIG. 7 shows a modification of the peg, indicated 58 a, which canreplace the pegs 58 of FIG. 2.

The foot portion, still indicated 60, of the peg 58 a is identical tothat of the pegs 58.

The peg 58 a differs from the peg 58 in that a mushroom-shaped appendage76 extends from its outer end, to be used for suspending articles ofvarious kinds.

Returning to FIG. 2, also the side faces 20 of the block 12 havecylindrical seats 78 in the piece 28.

Other pegs 80 can be associated with the said seats 78 and have acylindrical foot portion 82 which can be fitted into the seats 78.

As an example, the lateral pegs 80 can be fixed to the block piece 28 bymeans of screws such as 84.

Referring to FIG. 8, each slat 16 has, at its ends, end parts 86provided with hook-shaped formations 88 which embrace the recessedportions of the pegs 58.

Preferably, the hook-shaped formations 88 are resilient and embrace therecessed portions of the pegs 58 over an arc of circumference which isslightly wider than 180°, so that the formations 88 hook themselvesaround the pegs 58 with a snap fit.

What is claimed is:
 1. A collapsible three-dimensional framework, suchas a display stand, including a plurality of tubular rods (10) connectedto each other by means of articulation joints, each of which jointsconsists of a block (12) of a substantially parallelepipedal shape whichhas a plurality of cavities (18) each of which is open on a respectiveside face (20) and on a back face (22) of the block (12), and in whichcavities there are inserted the ends of respective rods (10) which areconnected to the block (12) by transverse pivot pins (24), fastened tothe rods (10), extend from the rods in diametrically opposite positionsand are engaged in respective articulation seats (32) formed in theblock (12) and open to the corresponding cavities (18) in oppositelateral positions, in that the block (12) is subdivided into two piecess(28, 30) which match with each other according to a separation planewhich is parallel to its back face (22) and located in correspondencewith the articulation seats (32) each of which are located in only oneof the two pieces, and in that two pieces (28, 30) of the block (12) aresecured to each other by relaesable fastening means (40, 42) in such amanner as to allow the insertion of the pivot pins (24) with a movementsubstantially perpendicular to the separation plane when the two pieces(28, 30) of the block (12) are separate and to entrap the pivot pins(24) in the seats (32) when these two pieces are joined to each other.2. A framework according to claim 1, characterized in that thetransverse pivot pins (24) of the rods (10) are constituted by resilienttubular split dowels which are driven in diametrically opposite holes(26) of the rods.
 3. A framework according to claim 1, characterized inthat the said releasable fastening means are constituted by a clampingscrew (40) which extends centrally in the two pieces (28, 30) of theblock (12), perpendicularly to its separation plane, and to which a nut(42) is associated.
 4. A framework according to claim 3, characterizedin that at least two opposite blocks (12) have a spacer tubular rod (14)associated thereto, in that the screws (40 a) of said blocks (12) extendin the corresponding ends of the spacer rod (14), and in that internallythreaded bushings (54) are driven in said ends and are associated in themanner of nuts to said screws (40 a).
 5. A framework according to claim4, characterized in that the spacer tubular rods (14) are in twosections (44, 46), each of which is secured to a respective block (12)and whose ends remote from the corresponding sections are provided withmutual coupling means (48, 50).
 6. A framework according to claim 1,wherein the articulation seats are in the form of recesses which areopen both to the corresponding cavities (18) and on a face (34) of thesaid piece of the block (12) which coincides with the separation plane,and in that the other piece (30) of the block (12) has, in theseparation plane, flat surfaces (36) which close the outlets of therecesses (32) in the said plane to entrap the pivot pins (24) of rods(10).
 7. A framework according to claim 6, characterized in that thepiece of the block (12) which contains the recesses (32) which receivethe pivot pins (24) is the piece (28) opposite to that which has theback face (22) and has, in the direction perpendicular to that of theseparation plane, a relatively great thickness, while the other piece(30) of the block (12) has a relatively small thickness.
 8. A frameworkaccording to claim 1, characterized in that the block (12) has, at leaston its front face (56) remote from its back face (22) at least oneprofiled peg or button (58, 58 a) to which accessories can be fixed. 9.A framework according to claim 8, characterized in that the block (12)has, at least on one of its side faces (20), at least one profiled pegor button (80) to which accessories can be affixed.
 10. A frameworkaccording to claim 8, characterized in that the profiled pegs or buttons(58, 58 a, 80) are constituted by pieces distinct from the correspondingpiece (28) of the block (12) and which have foot portions (60, 82), andin that such piece (28) of the block (12) has corresponding seats (62,78) into which the foot pieces can be fitted.
 11. A framework accordingto claim 10, characterized in that the foot portions (60) include afirst cylindrical section (64) of a greater diameter from which thereextends a second resilient tubular cylindrical section (66) of a smallerdiameter which ends with an annular outer rim (68), and in that thecorresponding seats (62) have a first cylindrical section (70) of agreater diameter to receive the said first section (64) of the footportion (60) and a second cylindrical (72) of a smaller diameter toreceive the second section (66) of the foot portion (60), which secondsection (66) extends through a wall (74) of the block piece (28), thearrangement being such that said rim (68), when the foot portion (60) ispushed home, is snap engaged around the inner mouth of the secondsection (72).
 12. A framework according to claim 8, characterized inthat the pegs (58) have recessed portions, and the framework includessupport slats (16) which have end pieces (86) provided with hook-shapedformations (88) which embrace with a snap fit the recessed potions ofthe pegs (58).
 13. An articulation joint in the form of a block for acollapsible three-dimensional framework, such as a display stand, theframework including a plurality of tubular rods (10) connected to eachother by means of articulation joints, wherein the joint consists of ablock (12) of a substantially parallelepipedal shape which has aplurality of cavities (18) each of which is open on a respective sideface (20) and on a back face (22) of the block (12), which cavities areadapted to the insertion of the ends of respective rods (10) of theframework which are adapted to be connected to the block (12) bytransverse pivot pins (24) which extend from the rods in diametricallyopposite positions, wherein the block (12) has articulation seats (32)formed therein and open to corresponding cavities (18) in oppositelateral positions to receive transverse pivot pins (24) which extendfrom the rods (10) in diametrically opposite positions, in that theblock (12) is subdivided into two pieces (28, 30) which match with eachother according to a separation plane which is parallel to its back face(22) and located in correspondence with the articulation seats (32)which are formed in only one of the two pieces of the block, and in thatthe two pieces (28, 30) of the block (12) are secured to each other byreleasable fastening means (40, 42) in such a manner as to allow theinsertion of the pivot pins (24) with a movement substantiallyperpendicular to the separation plane when the two pieces (28, 30) ofthe block (12) are separate and to entrap the pivot pins (24) in theseats (32) when these two pieces are joined to each other.
 14. Anarticulation joint according to claim 13, characterized in that the saidreleasable fastening means are constituted by a clamping screw (40)which extends centrally in the two pieces (28, 30) of the block (12),perpendicularly to its separation plane, and to which a nut (42) isassociated.
 15. A framework according to claim 13, wherein thearticulation seats are in the form of recesses which are open both tothe corresponding cavities (18) and on a face (34) of the said piece ofthe block (12) which coincides with the separation plane, and in thatthe other piece (30) of the block (12) has, in the separation plane,flat surfaces (36) which close the outlets of the recesses (32) in thesaid plane to entrap the pivot pins (24) of rods (10).
 16. Anarticulation joint according to claim 15, characterized in that thepiece of the block (12) which contains the recesses (32) which receivethe pivot pins (24) is the piece (28) opposite to that which has theback face (22) and has, in the direction perpendicular to that of theseparation plane, a relatively great thickness, while the other piece(30) of the block (12) has a relatively small thickness.
 17. Anarticulation joint according to claim 13, characterized in that theblock (12) has, at least on its front face (56) remote from its backface (22), at least one profiled peg or button (58, 58 a) to whichaccessories can be fixed.
 18. An articulation joint according to claim17, characterized in that the block (12) has, at least on one of itsside faces (20), at least one profiled peg or button (80) to whichaccessories can be affixed.
 19. An articulation joint according to claim13, characterized in that the block (12) has, at least on its front face(56) remote from its back face (22), at least one profiled peg or button(58, 58 a) to which accessories can be fitted.
 20. An articulation jointaccording to claim 19, characterized in that the foot portions (60)include a first cylindrical section (64) of a greater diameter fromwhich there extends a second resilient tubular cylindrical section (66)of a smaller diameter which ends with an annular outer rim (68), and inthat the corresponding seats (62) have a first cylindrical section (70)of a greater diameter to receive the said first section (64) of the footportion (60) and a second cylindrical (72) of a smaller diameter toreceive the second section (66) of the foot portion (60), which secondsection (66) extends through a wall (74) of the block piece (28), thearrangement being such that said rim (68), when the foot portion (60) ispushed home, is snap engaged around the inner mouth of the secondsection (72).